1. Field of the Invention
The present invention generally relates to a semiconductor device structure and a fabricating method thereof, and more particularly, to a resistor structure and a fabricating method thereof.
2. Description of the Prior Art
In the present age of information explosion, integrated circuits (ICs) have been broadly applied in every aspect of our daily life. Resistor device is one of the most indispensable passive devices in circuit design and application and which is applied to various electronic products, such as memories and logic circuits.
In a conventional IC, resistors are usually made of lightly doped polysilicon, and resistors having different resistances are usually made by using strip-shaped polysilicon having different cross-sectional areas and lengths.
More personalized and complicated electronic products have been constantly promoted along with the advancement of the electronic technology, and the design of every electronic product has been going towards lightweight and slimness in order to provide more comfort to the users.
Accordingly, metal gates are usually adopted in order to improve the efficiency of metal-oxide-semiconductor (MOS) transistor devices. Thus, in a process for integrating a MOS transistor device and a resistor, a polysilicon layer in the resistor is formed on a metal layer and which results in reduction of the resistance of the resistor and accordingly reduces the efficiency thereof.